Major Collision Investigation Unit detectives are investigating following a collision between a car and motorbike in Carrum Downs last night.
The collision occurred at the intersection of Frankston-Dandenong Road and Centenary Street just after 5.30pm.
The 51-year-old male rider from Carum Downs was airlifted to hospital with life-threatening injuries.
The 44-year-old Seaford woman who was driving the car, stopped at the scene and is assisting police with their enquiries.
Investigators would like to speak to anyone who witnessed the collision or who has dash cam footage to contact Crime Stoppers on 1800 333 000 or submit a confidential report via www.crimestoppersvic.com.au